Human-being perceive depth of an object by small difference of the object seen by the left eye and the right eye, to recognize a stereographic image. Such a phenomenon that the left eye and the right eye see different images is referred to as parallax. The 3D (three dimensional) image display technologies artificially create parallax between the left eye and the right eye to make the left eye and the right eye receive two different images respectively. Eventually, the brain processes the two images obtained by the left eye and the right eye to produce the feeling of observing a real 3D object.
Like a conventional display apparatus, each pixel in a 3D display apparatus displays colors by mixing lights from several sub-pixels, for example, each pixel consists of one red sub-pixel, one green sub-pixel and one blue sub-pixel. In order to improve the visual effect, people raise higher requirement on the resolution of the display apparatus, which requires a smaller size of sub-pixels. However, due to the limitation of the process, the size of sub-pixels cannot be downsized infinitely. Therefore, how to improve the display effect of a 3D display apparatus in a case in which the sub-pixel has a certain size is a problem for those skilled in the art to solve.